The two primers MF (5'-GAGAGCAAGCACCCTTTCCT-3') and MR (5'-GAGAGTCCTGTGATTCCCCT-3') were used to amplify the complete coding region of MCIR gene from the 108 individual sheep .
PGR products of MCIR fragments were cleaned and sequenced by the Advanced Genetic Technologies Center (http://www.
The amplification of the MCIR gene generated a PGR product of 1,170 bp in length from 41 Najdi, 36 Naeimi, 18 Herri, and 13 Sawaknee sheep.
Generally, Najdi sheep showed the highest allelic variation in the MCIR gene, followed by Herri then Naeimi.
Based on the eight MCIR haplotypes recovered during this study, 36 expected haplotype combinations were constructed.
The MCIR protein is a highly polymorphic 7-transmembrane G protein-coupled receptor .
When these two mutations were introduced into mouse MCIR receptors, the Met73Lys mutation showed constitutive activation whereas the Aspl21Asn mutation was required for high affinity ligand binding .
Vage et ai  showed that the Met73Lys mutation leads to a constitutive activation of MCIR in sheep.
The present study supports the suggestion that the two independent nonsynonymous mutations (Met73Lys and Aspl21Asn) in MCIR are associated with b pigmentation in sheep.
Mutations in MCIR gene determine black coat color phenotype in Chinese sheep.